4317 Case Hardening Steel
|4317 is a 1.8% chromium - nickel - molybdenum high hardenability, case hardening (carburizing) steel, generally supplied in the annealed condition with a maximum brinell hardness of 229 (Rc22).
Characterised by high core strength and toughness in medium to large sections with case hardness up to Rc62 when carburized, hardened and tempered.
4317 can also be used (uncarburised) as a high tensile steel, which when suitably hardened and tempered can be utilized for various applications requiring good tensile strength and toughness.
Pre hardened and tempered (uncarburized) 4317 can be further surface hardened by nitriding but will not respond satisfactorily to flame or induction hardening due to its low carbon content.
4317 (carburized) is used extensively by all industry sectors for components and shafts requiring high surface wear resistance, high core strength and impact properties.
Typical uses are: Heavy Duty Bushings and Bearings, Cam Followers, Clutch Dogs, Compressor Bolts, Extractors, Fan Shafts, Heavy Duty Gears, Pump Shafts, Sprockets, Tappets, Wear Pins, Wire Guides etc..
|Colour Code||Stocked Sizes|
|Red and White (Bar End)||Rounds|
|Min. %||Max. %|
|Tensile Strength Mpa||700|
|Yield Strength Mpa||520|
|Section Size mm||11||30||63|
|Tensile Strength Mpa||Min||1180||1080||980|
|Yield Strength Mpa||Min||835||785||685|
|Impact Charpy J||Min||41||41|
|Hardness||HB||350 - 415||320 - 385||290 - 375|
|Rc||39 - 44||35 - 42||31 - 41|
Do not forge below 850 oC.
Following completion of forging operation, work piece should be cooled as slowly as possible in sand or dry lime etc.
Note: Case hardening steels due to their low carbon content are less susceptable to cracking than medium or high carbon steels, and may therefore be heated and cooled more rapidly.
|Direct Quench: Cool from carburizing temperature to 820 oC - 840 oC, hold until temperature is uniform throughout the section. Quench in oil.Temper immediately while still hand warm.
Or: Cool from carburizing temperature to room temperature, re-heat to 820 oC - 840 oC and hold until temperature is uniform throughout the section and quench in oil.
|Suggested Pre-heat Temperature|